This invention relates to powered wheelchairs for use by handicapped and disabled persons.
Power wheelchairs are known and have been the subject of increasing development efforts to provide handicapped and disabled persons with independent mobility to assist handicapped and disabled persons in leading more normal lives.
Power wheelchairs known heretofore have, for the most part, resembled conventional, manual wheelchairs; indeed, many such power wheelchairs have merely been conventional wheelchairs equipped with motors. Use of such power wheelchairs sometimes results in the user feeling a stigma associated therewith in that unthoughtful persons may view the power wheelchair user in a quizzical or even offensive manner.
Additionally, known power wheelchairs suffer in that they tend to be large and are not particularly maneuverable. These large, difficult to maneuver power wheelchairs present difficulties for the power wheelchair user in navigating within conventional dwellings which have not been modified to accommodate such conventional power wheelchairs.
Typical conventional rear wheel drive power wheelchairs which are little more than manual wheelchairs equipped with motors, have turning circles of about 72 inches in diameter, whereas typical front wheel drive power wheelchairs known heretofore have, for the most part, turning circles in the neighborhood of 52 inches in diameter. These turning circles are too big for the user of a conventional power wheelchair to reverse the wheelchair direction by turning the wheelchair around within the corridor or hallway of a conventional office building or most homes.
Dual drive motor power wheelchairs are known; one is illustrated in U.S. Pat. No. 5,540,297. Other power wheelchairs are disclosed in U.S. Pat. Nos. 4,513,832; 4,538,857; 5,094,310; 5,145,020 and 5,366,037.
Front wheel drive power wheelchairs are sold by Permobile, Inc. in Woburn, Mass. and typically have the driving front wheels at the extreme forward end of the vehicle chassis thereby requiring substantial space in order to turn the front wheel drive power wheelchair because the axis of rotation of the chair, upon turning, is at the mid-point of the drive wheel axes, which is at the extreme forward end of the chair.
In one of its aspects this invention provides a power wheelchair having a frame, a seat supported by the frame, a pair of drive wheels connected to the frame and rotatable about a transverse axis below a central portion of the seat with the drive wheel axis and seat positioned so that the drive wheel axis is forward of the cranial center of perception of a user of the power wheelchair.
In another of its aspects the invention provides a power wheelchair with the seat positioned so that the drive wheel axis is under and perhaps only slightly longitudinally ahead of the cranial center of perception of user of the power wheelchair.
In yet another of its aspects this invention provides a power wheelchair in which the drive wheel axis is at a substantially common longitudinal location with the center of cranial perception when the wheelchair user occupies the seat.
In yet another of its aspects this invention provides a power wheelchair in which the drive wheel axis is forward of the eyes of the wheelchair user when the wheelchair user is seated upright in the seat.
In yet another of its aspects this invention provides a power wheelchair in which the drive wheel axis is longitudinally intermediate of the power wheelchair user""s center of cranial perception and a manual control by which the power wheelchair user controls the power wheelchair.
In yet another of its aspects this invention provides a power wheelchair in which the wheelchair user""s cranial center of perception is at substantially a common longitudinal location with the center of gravity of the power wheelchair when the chair is unoccupied.
In yet another of its aspects this invention provides a power wheelchair in which a control joystick is used for single manual control of the wheelchair by the power wheelchair user and the drive wheel axis is longitudinally intermediate of the power wheelchair user""s center of cranial perception and the control joystick by which the power wheelchair user controls the power wheelchair when the wheelchair user is seated upright in the power wheelchair.